Yarn treating apparatus



1967 w. H. HILLS ETAL YARN TREATING APPAI UXTUS 2 Sheets-Sheet 1 Filed Nov. 12, 1963 INVENTORS WILLIAM H. HILLS EUELL K. McINTOSH JAMES R. WILLIAMS ATT 66EY Feb. 14, 1967 w. H. HILLS ETAL 3,303,548

YARN TREAT ING APPARATUS Filed NOV. 12, 1963 2 Sheets-Sheet 2 FIG.2.

INVENTORS WILLIAM H. HILLS EUELL K. MCINTOSH JAMES R. WILLIAMS ATT RNEY United States Patent 3,303,548 YARN TREATING APPARATUS William H. Hills and Euell K. McIntosh, Pensacola, Fla.,

The present invention relates to apparatus producing a textured yarn having superior tufting, knitting and weaving performance, and more particularly to such a yarn which is pre-bulked and coated with a particular composition for improving its performance.

For the past several years, there have been commercially available continuous filament thermoplastic yarns which possess latent bulking. The yarn was used in this form to make textile products, and the bulk developed after the end product had been partially or completely manufactured. For example, a carpet would 'be tufted using such yarns and the bulk would be developed when the carpet was dyed. Carpets made of yarn having undeveloped bulk typically had a high incidence of flaws and pulled loops, which had to be repaired by hand, thus increasing the cost of producing satisfactory carpeting. Such unbu'lked yarn gave certain other difiiculties in handling and in subsequent manufacturing operations.

According to the present invention, such yarn is coated with a particular composition and pre bulke-d to markedly improve its performance in subsequent manufacturing operations.

Accordingly a primary object of the invention is to provide apparatus for producing a continuous filament textured yarn which may be more readily incorporated into manufactured products.

A further object is to provide apparatus for producing yarn which exhibits greatly improved tufting performance.

A further object is to provide apparatus for producing yarn which is pre-bulked and which has, thereon a coating to further improve performance in subsequent manufacturing operations.

A further object is to provide apparatus which reduces to a minimum steam condensation in undesired places.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a more complete understanding of the nature and objects of the invention, reference should be made to the following detailed description taken in connection with the accompanying drawings, in which:

FIGURE 1 is a schematic perspective view of an exemplary form of apparatus for practicing the method according to the present invention; and

FIGURE 2 is a side elevation view, partly in section, of the preferred bulking chamber of FIGURE 1.

Referring now generally to FIGURE 1, yarn 20 having latent bulking is supplied from a source 22. As schematically illustrated, source 22 may be the apparatus disclosed in US. Patent 3,024,516 to J. E. Bromley et al., or may be any other equivalent source, such as a different apparatus or a bobbin of latent-crimped yarn. An applicator 24 applies silica dispersed in a liquid carrier to the yarn, as will be more fully explained. The wetted yarn 20 is fed by a pair of nip rolls 26 to a treating chamber 28 wherein it is exposed to sufficient heat to simultaneously bulk the yarn and evaporate the liquid component applied by applicator 24. Yarn 20 is then fed by a second pair of nip rolls 30 to a suitable take-up mechanism 32 which takes up the yarn in the form of a package 34.

Referring now more specifically to FIGURE 1, the applicator 24 is illustrated in the form of a slowly rotating wheel 36, against the periphery of which yarn 20 runs. The lower surface of wheel 36 may be immersed in a container of the dispersion. As will be understood, the amount of dispersion thus applied to yarn 20 by wheel 36 may be readily controlled by controlling the rate of revolution of wheel 36. Sufiicient dispersion should be applied by wheel 36 so that the silica deposited on the yarn is between 0.1 and 5.0 percent of the Yarn weight. Water is a convenient carrier. Preferably, the silica is in the form of a colloidal dispersion, with particle sizes of a few hundred angstroms. For example, the particle size may be in the range of from 350 to 400 angstroms in diameter. Advantageously, such a colloidal dispersion may be slightly basic to prevent precipitation of the silica. A pH of between 7.0 and 10.0 is satisfactory.

Yarn 20 is next fed by nip rolls 26 into the treating chamber 28. Referring now to FIGURE 2, chamber 28 comprises an elongated heated central tube 40 through which yarn 20 is passed. A steam chamber 42 surrounds tube 40 over most of the length of the tube. Chamber 42 is Welded or otherwise sealed to the outside of tube 40 near its ends, and is jacketed with a suitable layer 43 of insulation. High pressure steam is admitted to chamber 42 by supp-1y pipe 44, so that the walls of tube 40 are heated, and is exhausted by an exhaust line or pipe 46.

When the steam supplied by pipe 44 has a comparatively low temperature, such as 350 F., it is desirable to supply more heat to the yarn than would be feasible by simple radiation from the walls of tube 40 if economical yarn speeds are to be attained in a reasonably short tube 40. According to the preferred embodiment of the present invention, steam is introduced into the interior of tube 40 in order to improve heat transfer to yarn 20. An annular expansion chamber 48 surrounds and separates the upper end of tube 40 from steam chamber 42. Several relatively large apertures 50 connect the interior of expansion chamber 48 and tube 40. A restricted orifice 52 is provided in the walls dividing chamber 48 from chamber 42, to permit a small amount of the high-pressure steam in chamber 42 to bleed into chamber 48. The steam thus admitted into chamber 48 expands and dissipates through apertures 50 into the central tube 40 at a sufiiciently low velocity that the yarn is not unduly agitated. Sufiicient heat is supplied through the walls of expansion chamber 48 to maintain the low-pressure steam therein at near the temperature of the high-pressure steam in chamber 42.

Referring now to FIGURES 1 and 2, the steam fed into tube 40 from expansion chamber 48, as well as the steam generated in tube 40 by evaporation of the water applied by wheel 36, must be disposed of to prevent condensation on surrounding apparatus. As best seen in FIGURE 1, this steam is withdrawn by an exhaust nozzle 54 partly surrounding the upper end of tube 40. The illustrated nozzle 54 is formed from a flattened region in a vacuum line or pipe 56 which is connected to a convenient vacuum source (not illustrated).

For optimum and most economical operation, the suction applied by nozzle 54 should be just sufficient to capture the steam issuing from tube 40, otherwise a draft might be created which would hamper proper development of the bulk in the yarn as well as being wasteful of vacuum. A simple and effective suction control is illustrated at 58. The upper wall of the flattened region of pipe 56 is pierced by a transverse slot 60. An upstanding bracket 62 is mounted on pipe 56 adjacent to slot 60, and supports thereon an adjustable valve plate 64. A screw 66 extending through :a vertically elongated slot 68 (FIGURE 1) in plate 64 is threaded into bracket 62 to permit adjustable positioning of plate 64 within slot 60, so that plate 64 blocks a selected portion of the cross section of pipe 56. This permits adjustment of the suction applied to nozzle 54 to its optimum degree.

An aspirator apparatus 68 is provided to simplify stringing up of the yarn through the tube 40. Aspirator apparatus 68 includes an air discharge nozzle 70 which is mounted so as to extend downwardly into the upper portion of tube 40 for discharge of compressed air through tube 40. A manual air supply valve 72 connects nozzle 70 to a suitable source of compressed air (not illustrated). When valve 72 is actuated, the compressed air supplied by nozzle 70 propels the yarn supplied by feed rolls 26 downwardly through tube 40 to rolls 30, at which point the operator may thread the yarn between feed rolls 30 and then to the take-up mechanism 32. It will be understood that air is thus supplied through nozzle 70 only during stringing up, and not during the normal operation of the treating chamber.

Referring again to FIGURE 2, a removable plug 74 is provided through the walls defining steam chamber 42, to permit direct access to the orifice 52 for cleaning or adjustment of the orifice. If orifice 52 in turn is formed in a removable plug in the walls defining chamber 48, the orifice plug may be readily removed through the opening in the walls defining chamber 42 for inspection or repair.

The following values are given solely by way of example to illustrate the mode of operation contemplate-d. The steam admitted through pipe 44 was at 90 pounds per square inch gauge and 350 F. The single orifice 52 was 0.020 inch in diameter, while each of the apertures 50 were of approximately inch diameter. Tube 40 was 11 inches long, and was surrounded by chamber 42 over 9 inches of its length.

As a result, the walls of tube 40 are maintained at approximately 350 F. and the interior of the tube had supplied thereto a small amount of steam at atmospheric pressure and 350 F. through orifice 52 and apertures 50. The wetted yarn fed through tube 40 was thus supplied with sufficient heat to evaporate the carrier (water) and to simultaneously develop the latent bulk possessed by the yarn. It will be understood that the length of tube 40 and chamber 42 may be increased or decreased depending upon the speed of the yarn 20 through treating chamber 28, the exemplary values given being suitable for a yarn speed of 175 y.p.m.

The relative speeds of nip rolls 26 and nip rolls 30 should be adjusted so that there is substantially no tension applied to yarn 20 While in treating chamber 28, in order to avoid destroying the developed bulk. In one successful embodiment of the invention, nip rolls 26 had a percent greater peripheral velocity than nip rolls 30, to permit a 10 percent reduction in length of the yarn as the bulk is developed.

To illustrate the efiiciency of the present invention, the following data was obtained by tufting carpets with nylon yarns of 136 filaments and total of 2460 denier. Carpet made with the control yarn, which was not treated with silica and which had not had its bulk developed, had an average of 3.24 flaws requiring mending in a given area. When the yarn was pre-bulked but not silica-coated, the same given area had 2.58 flaws, an improvement in tufting performance by a factor of 1.25. When the yarn was silica-coated but not pre-bulked, the same given area had 0.83 flaws, an improvement by a factor of 3.90. Carpet made with silica-coated and pre-bulked yarn according to the present invention, at a treating level of 0.35 percent silica on the yarn, had an average of only 0.023 flaws in the same given area. This shows improved tufting performance by reduction of carpet flaws by a factor of about 140, which improvement is far greater than would be expected by the cumulative effects of the individual steps. In addition, superior yarn cover is provided as compared to control.

In the above description and the accompanying drawings, there has been disclosed a novel apparatus for producing continuous filament textured yarn. The disclosed apparatus may readily be added to or incorporated in existing yarn treating apparatus. Orifice 52 and expansion chamber 48 permit the application of high-temperature, low-velocity steam to the yarn being treated in order to permit higher yarn treating speeds without adverse effects on the yarn. Since the yarn is over-fed by rolls 26 through the treating chamber 28, the yarn is under substantially no tension during the heat-treating operation, which permits effective development of the latent bulk in the yarn. The adjustable vacuum nozzle positioned at the upper end of the treating chamber efliciently removes the steam issuing from the treating chamber, thus preventing condensation of this steam on the surrounding apparatus, while the illustrated aspirator tube 70 permits simple stringing up of the yarn through the treating chamber.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efiiciently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of langauge, might be said to fall therebetween.

Having described our invention, what we claim as new and desire to secure by Letters Patent is:

1. Yarn treating apparatus comprising, in combination:

(a) walls defining a substantially vertical elongated passageway having an upper open end and a lower open end,

(b) means defining with said walls an expansion chamber surrounding said passageway near one of said ends,

(c) a steam chamber containing pressurized steam surrounding said expansion chamber and said passageway,

(d) means defining a restricted orifice connecting said steam chamber to said expansion chamber whereby a small amount of steam is admitted to said expansion chamber,

(e) means defining at least one aperture connecting said expansion chamber to said pasageway, said at least one aperture having a much larger cross-sectional area than said orifice, whereby the steam admitted to said expansion chamber is permitted to diffuse at low velocity into said passageway, and

(f) an exhaust nozzle, mounted exteriorly of and adjacent one of said ends of said passageway, supplying just sufficient vacuum to take up the steam issuing from said one of said ends.

2. The apparatus defined in claim 1, wherein said one of said ends is said upper end.

3. The apparatus defined in claim 2, further comprismg:

(a) means for feeding said yarn into one of said ends of said passageway at a given speed,

(b) and means for Withdrawing said yarn from the other of said ends of said passageway at a speed less than said given speed.

References Cited by the Examiner UNITED STATES PATENTS 6 2,468,081 4/1949 Koster 28-59.5 X 2,584,043 1/1952 Oberly 8-149.3 X 3,031,770 5/1962 Githens et a1. 34-68 MERVIN STEIN, Primary Examiner.

DONALD W. PARKER, H. S. JAUDON,

Assistant Examiners. 

1. YARN TREATING APPARATUS COMPRISING, IN COMBINATION: (A) WALLS DEFINING A SUBSTANTIALLY VERTICAL ELONGATED PASSAGEWAY HAVING AN UPPER OPEN END AND A LOWER OPEN END, (B) MEANS DEFINING WITH SAID WALLS AN EXPANSION CHAMBER SURROUNDING SAID PASSAGEWAY NEAR ONE OF SAID ENDS, (C) A STEAM CHAMBER CONTAINING PRESSURIZED STEAM SURROUNDING SAID EXPANSION CHAMBER AND SAID PASSAGEWAY, (D) MEANS DEFINING A RESTRICTED ORIFICE CONNECTING SAID STEAM CHAMBER TO SAID EXPANSION CHAMBER WHEREBY A SMALL AMOUNT OF STEAM IS ADMITTED TO SAID EXPANSION CHAMBER, (E) MEANS DEFINING AT LEAST ONE APERTURE CONNECTING SAID EXPANSION CHAMBER TO SAID PASSAGEWAY, SAID AT LEAST ONE APERTURE HAVING A MUCH LARGER CROSS-SECTIONAL AREA THAN SAID ORIFICE, WHEREBY THE STEAM ADMITTED TO SAID EXPANSION CHAMBER IS PERMITTED TO DIFFUSE AT LOW VELOCITY INTO SAID PASSAGEWAY, AND (F) AN EXHAUST NOZZLE, MOUNTED EXTERIORLY OF AND ADJACENT ONE OF SAID ENDS OF SAID PASSAGEWAY, SUPPLYING JUST SUFFICIENT VACUUMM TO TAKE UP THE STEAM ISSUIGN FROM SAID ONE OF SAID ENDS. 